// Formatting library for C++ - experimental range support // // Copyright (c) 2012 - present, Victor Zverovich // All rights reserved. // // For the license information refer to format.h. // // Copyright (c) 2018 - present, Remotion (Igor Schulz) // All Rights Reserved // {fmt} support for ranges, containers and types tuple interface. #ifndef FMT_RANGES_H_ #define FMT_RANGES_H_ #include #include #include #include "format.h" FMT_BEGIN_NAMESPACE namespace detail { template auto copy(const Range& range, OutputIt out) -> OutputIt { for (auto it = range.begin(), end = range.end(); it != end; ++it) *out++ = *it; return out; } template auto copy(const char* str, OutputIt out) -> OutputIt { while (*str) *out++ = *str++; return out; } template auto copy(char ch, OutputIt out) -> OutputIt { *out++ = ch; return out; } template auto copy(wchar_t ch, OutputIt out) -> OutputIt { *out++ = ch; return out; } // Returns true if T has a std::string-like interface, like std::string_view. template class is_std_string_like { template static auto check(U* p) -> decltype((void)p->find('a'), p->length(), (void)p->data(), int()); template static void check(...); public: static constexpr const bool value = is_string::value || std::is_convertible>::value || !std::is_void(nullptr))>::value; }; template struct is_std_string_like> : std::true_type {}; template class is_map { template static auto check(U*) -> typename U::mapped_type; template static void check(...); public: #ifdef FMT_FORMAT_MAP_AS_LIST // DEPRECATED! static constexpr const bool value = false; #else static constexpr const bool value = !std::is_void(nullptr))>::value; #endif }; template class is_set { template static auto check(U*) -> typename U::key_type; template static void check(...); public: #ifdef FMT_FORMAT_SET_AS_LIST // DEPRECATED! static constexpr const bool value = false; #else static constexpr const bool value = !std::is_void(nullptr))>::value && !is_map::value; #endif }; template struct conditional_helper {}; template struct is_range_ : std::false_type {}; #if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800 # define FMT_DECLTYPE_RETURN(val) \ ->decltype(val) { return val; } \ static_assert( \ true, "") // This makes it so that a semicolon is required after the // macro, which helps clang-format handle the formatting. // C array overload template auto range_begin(const T (&arr)[N]) -> const T* { return arr; } template auto range_end(const T (&arr)[N]) -> const T* { return arr + N; } template struct has_member_fn_begin_end_t : std::false_type {}; template struct has_member_fn_begin_end_t().begin()), decltype(std::declval().end())>> : std::true_type {}; // Member function overload template auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast(rng).begin()); template auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast(rng).end()); // ADL overload. Only participates in overload resolution if member functions // are not found. template auto range_begin(T&& rng) -> enable_if_t::value, decltype(begin(static_cast(rng)))> { return begin(static_cast(rng)); } template auto range_end(T&& rng) -> enable_if_t::value, decltype(end(static_cast(rng)))> { return end(static_cast(rng)); } template struct has_const_begin_end : std::false_type {}; template struct has_mutable_begin_end : std::false_type {}; template struct has_const_begin_end< T, void_t< decltype(detail::range_begin(std::declval&>())), decltype(detail::range_end(std::declval&>()))>> : std::true_type {}; template struct has_mutable_begin_end< T, void_t())), decltype(detail::range_end(std::declval())), // the extra int here is because older versions of MSVC don't // SFINAE properly unless there are distinct types int>> : std::true_type {}; template struct is_range_ : std::integral_constant::value || has_mutable_begin_end::value)> {}; # undef FMT_DECLTYPE_RETURN #endif // tuple_size and tuple_element check. template class is_tuple_like_ { template static auto check(U* p) -> decltype(std::tuple_size::value, int()); template static void check(...); public: static constexpr const bool value = !std::is_void(nullptr))>::value; }; // Check for integer_sequence #if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900 template using integer_sequence = std::integer_sequence; template using index_sequence = std::index_sequence; template using make_index_sequence = std::make_index_sequence; #else template struct integer_sequence { using value_type = T; static FMT_CONSTEXPR size_t size() { return sizeof...(N); } }; template using index_sequence = integer_sequence; template struct make_integer_sequence : make_integer_sequence {}; template struct make_integer_sequence : integer_sequence {}; template using make_index_sequence = make_integer_sequence; #endif template using tuple_index_sequence = make_index_sequence::value>; template ::value> class is_tuple_formattable_ { public: static constexpr const bool value = false; }; template class is_tuple_formattable_ { template static std::true_type check2(index_sequence, integer_sequence); static std::false_type check2(...); template static decltype(check2( index_sequence{}, integer_sequence< bool, (is_formattable::type, C>::value)...>{})) check(index_sequence); public: static constexpr const bool value = decltype(check(tuple_index_sequence{}))::value; }; template FMT_CONSTEXPR void for_each(index_sequence, Tuple&& t, F&& f) { using std::get; // Using a free function get(Tuple) now. const int unused[] = {0, ((void)f(get(t)), 0)...}; ignore_unused(unused); } template FMT_CONSTEXPR void for_each(Tuple&& t, F&& f) { for_each(tuple_index_sequence>(), std::forward(t), std::forward(f)); } template void for_each2(index_sequence, Tuple1&& t1, Tuple2&& t2, F&& f) { using std::get; const int unused[] = {0, ((void)f(get(t1), get(t2)), 0)...}; ignore_unused(unused); } template void for_each2(Tuple1&& t1, Tuple2&& t2, F&& f) { for_each2(tuple_index_sequence>(), std::forward(t1), std::forward(t2), std::forward(f)); } namespace tuple { // Workaround a bug in MSVC 2019 (v140). template using result_t = std::tuple, Char>...>; using std::get; template auto get_formatters(index_sequence) -> result_t(std::declval()))...>; } // namespace tuple #if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920 // Older MSVC doesn't get the reference type correctly for arrays. template struct range_reference_type_impl { using type = decltype(*detail::range_begin(std::declval())); }; template struct range_reference_type_impl { using type = T&; }; template using range_reference_type = typename range_reference_type_impl::type; #else template using range_reference_type = decltype(*detail::range_begin(std::declval())); #endif // We don't use the Range's value_type for anything, but we do need the Range's // reference type, with cv-ref stripped. template using uncvref_type = remove_cvref_t>; template FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set) -> decltype(f.set_debug_format(set)) { f.set_debug_format(set); } template FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {} // These are not generic lambdas for compatibility with C++11. template struct parse_empty_specs { template FMT_CONSTEXPR void operator()(Formatter& f) { f.parse(ctx); detail::maybe_set_debug_format(f, true); } ParseContext& ctx; }; template struct format_tuple_element { using char_type = typename FormatContext::char_type; template void operator()(const formatter& f, const T& v) { if (i > 0) ctx.advance_to(detail::copy_str(separator, ctx.out())); ctx.advance_to(f.format(v, ctx)); ++i; } int i; FormatContext& ctx; basic_string_view separator; }; } // namespace detail template struct is_tuple_like { static constexpr const bool value = detail::is_tuple_like_::value && !detail::is_range_::value; }; template struct is_tuple_formattable { static constexpr const bool value = detail::is_tuple_formattable_::value; }; template struct formatter::value && fmt::is_tuple_formattable::value>> { private: decltype(detail::tuple::get_formatters( detail::tuple_index_sequence())) formatters_; basic_string_view separator_ = detail::string_literal{}; basic_string_view opening_bracket_ = detail::string_literal{}; basic_string_view closing_bracket_ = detail::string_literal{}; public: FMT_CONSTEXPR formatter() {} FMT_CONSTEXPR void set_separator(basic_string_view sep) { separator_ = sep; } FMT_CONSTEXPR void set_brackets(basic_string_view open, basic_string_view close) { opening_bracket_ = open; closing_bracket_ = close; } template FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { auto it = ctx.begin(); if (it != ctx.end() && *it != '}') FMT_THROW(format_error("invalid format specifier")); detail::for_each(formatters_, detail::parse_empty_specs{ctx}); return it; } template auto format(const Tuple& value, FormatContext& ctx) const -> decltype(ctx.out()) { ctx.advance_to(detail::copy_str(opening_bracket_, ctx.out())); detail::for_each2( formatters_, value, detail::format_tuple_element{0, ctx, separator_}); return detail::copy_str(closing_bracket_, ctx.out()); } }; template struct is_range { static constexpr const bool value = detail::is_range_::value && !detail::is_std_string_like::value && !std::is_convertible>::value && !std::is_convertible>::value; }; namespace detail { template struct range_mapper { using mapper = arg_mapper; template , Context>::value)> static auto map(T&& value) -> T&& { return static_cast(value); } template , Context>::value)> static auto map(T&& value) -> decltype(mapper().map(static_cast(value))) { return mapper().map(static_cast(value)); } }; template using range_formatter_type = formatter>{}.map( std::declval()))>, Char>; template using maybe_const_range = conditional_t::value, const R, R>; // Workaround a bug in MSVC 2015 and earlier. #if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910 template struct is_formattable_delayed : is_formattable>, Char> {}; #endif } // namespace detail template struct range_formatter; template struct range_formatter< T, Char, enable_if_t>, is_formattable>::value>> { private: detail::range_formatter_type underlying_; basic_string_view separator_ = detail::string_literal{}; basic_string_view opening_bracket_ = detail::string_literal{}; basic_string_view closing_bracket_ = detail::string_literal{}; public: FMT_CONSTEXPR range_formatter() {} FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type& { return underlying_; } FMT_CONSTEXPR void set_separator(basic_string_view sep) { separator_ = sep; } FMT_CONSTEXPR void set_brackets(basic_string_view open, basic_string_view close) { opening_bracket_ = open; closing_bracket_ = close; } template FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { auto it = ctx.begin(); auto end = ctx.end(); if (it != end && *it == 'n') { set_brackets({}, {}); ++it; } if (it != end && *it != '}') { if (*it != ':') FMT_THROW(format_error("invalid format specifier")); ++it; } else { detail::maybe_set_debug_format(underlying_, true); } ctx.advance_to(it); return underlying_.parse(ctx); } template auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) { detail::range_mapper> mapper; auto out = ctx.out(); out = detail::copy_str(opening_bracket_, out); int i = 0; auto it = detail::range_begin(range); auto end = detail::range_end(range); for (; it != end; ++it) { if (i > 0) out = detail::copy_str(separator_, out); ctx.advance_to(out); out = underlying_.format(mapper.map(*it), ctx); ++i; } out = detail::copy_str(closing_bracket_, out); return out; } }; enum class range_format { disabled, map, set, sequence, string, debug_string }; namespace detail { template struct range_format_kind_ : std::integral_constant, T>::value ? range_format::disabled : is_map::value ? range_format::map : is_set::value ? range_format::set : range_format::sequence> {}; template struct range_default_formatter; template using range_format_constant = std::integral_constant; template struct range_default_formatter< K, R, Char, enable_if_t<(K == range_format::sequence || K == range_format::map || K == range_format::set)>> { using range_type = detail::maybe_const_range; range_formatter, Char> underlying_; FMT_CONSTEXPR range_default_formatter() { init(range_format_constant()); } FMT_CONSTEXPR void init(range_format_constant) { underlying_.set_brackets(detail::string_literal{}, detail::string_literal{}); } FMT_CONSTEXPR void init(range_format_constant) { underlying_.set_brackets(detail::string_literal{}, detail::string_literal{}); underlying_.underlying().set_brackets({}, {}); underlying_.underlying().set_separator( detail::string_literal{}); } FMT_CONSTEXPR void init(range_format_constant) {} template FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { return underlying_.parse(ctx); } template auto format(range_type& range, FormatContext& ctx) const -> decltype(ctx.out()) { return underlying_.format(range, ctx); } }; } // namespace detail template struct range_format_kind : conditional_t< is_range::value, detail::range_format_kind_, std::integral_constant> {}; template struct formatter< R, Char, enable_if_t::value != range_format::disabled> // Workaround a bug in MSVC 2015 and earlier. #if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910 , detail::is_formattable_delayed #endif >::value>> : detail::range_default_formatter::value, R, Char> { }; template struct tuple_join_view : detail::view { const std::tuple& tuple; basic_string_view sep; tuple_join_view(const std::tuple& t, basic_string_view s) : tuple(t), sep{s} {} }; // Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers // support in tuple_join. It is disabled by default because of issues with // the dynamic width and precision. #ifndef FMT_TUPLE_JOIN_SPECIFIERS # define FMT_TUPLE_JOIN_SPECIFIERS 0 #endif template struct formatter, Char> { template FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { return do_parse(ctx, std::integral_constant()); } template auto format(const tuple_join_view& value, FormatContext& ctx) const -> typename FormatContext::iterator { return do_format(value, ctx, std::integral_constant()); } private: std::tuple::type, Char>...> formatters_; template FMT_CONSTEXPR auto do_parse(ParseContext& ctx, std::integral_constant) -> decltype(ctx.begin()) { return ctx.begin(); } template FMT_CONSTEXPR auto do_parse(ParseContext& ctx, std::integral_constant) -> decltype(ctx.begin()) { auto end = ctx.begin(); #if FMT_TUPLE_JOIN_SPECIFIERS end = std::get(formatters_).parse(ctx); if (N > 1) { auto end1 = do_parse(ctx, std::integral_constant()); if (end != end1) FMT_THROW(format_error("incompatible format specs for tuple elements")); } #endif return end; } template auto do_format(const tuple_join_view&, FormatContext& ctx, std::integral_constant) const -> typename FormatContext::iterator { return ctx.out(); } template auto do_format(const tuple_join_view& value, FormatContext& ctx, std::integral_constant) const -> typename FormatContext::iterator { auto out = std::get(formatters_) .format(std::get(value.tuple), ctx); if (N > 1) { out = std::copy(value.sep.begin(), value.sep.end(), out); ctx.advance_to(out); return do_format(value, ctx, std::integral_constant()); } return out; } }; namespace detail { // Check if T has an interface like a container adaptor (e.g. std::stack, // std::queue, std::priority_queue). template class is_container_adaptor_like { template static auto check(U* p) -> typename U::container_type; template static void check(...); public: static constexpr const bool value = !std::is_void(nullptr))>::value; }; template struct all { const Container& c; auto begin() const -> typename Container::const_iterator { return c.begin(); } auto end() const -> typename Container::const_iterator { return c.end(); } }; } // namespace detail template struct formatter< T, Char, enable_if_t, bool_constant::value == range_format::disabled>>::value>> : formatter, Char> { using all = detail::all; template auto format(const T& t, FormatContext& ctx) const -> decltype(ctx.out()) { struct getter : T { static auto get(const T& t) -> all { return {t.*(&getter::c)}; // Access c through the derived class. } }; return formatter::format(getter::get(t), ctx); } }; FMT_BEGIN_EXPORT /** \rst Returns an object that formats `tuple` with elements separated by `sep`. **Example**:: std::tuple t = {1, 'a'}; fmt::print("{}", fmt::join(t, ", ")); // Output: "1, a" \endrst */ template FMT_CONSTEXPR auto join(const std::tuple& tuple, string_view sep) -> tuple_join_view { return {tuple, sep}; } template FMT_CONSTEXPR auto join(const std::tuple& tuple, basic_string_view sep) -> tuple_join_view { return {tuple, sep}; } /** \rst Returns an object that formats `initializer_list` with elements separated by `sep`. **Example**:: fmt::print("{}", fmt::join({1, 2, 3}, ", ")); // Output: "1, 2, 3" \endrst */ template auto join(std::initializer_list list, string_view sep) -> join_view { return join(std::begin(list), std::end(list), sep); } FMT_END_EXPORT FMT_END_NAMESPACE #endif // FMT_RANGES_H_